It has long been known to produce beverages of various formulations. Improved and new formulations are desirable to achieve desired nutritional characteristics, flavor, shelf life, and other objectives. For example, it would be desirable to prevent the development of brown color in tea beverages that often occurs over time. There are two types of browning: enzymatic browning and non-enzymatic browning. Enzymatic browning occurs when fresh food or beverage products are exposed to air and there are active enzymes present within the food or beverage product. When an apple slice or banana turns brown, it is usually due to polyphenol oxidase enzyme activity. In contrast, non-enzymatic browning is the result of in situ oxidation of ingredients within juice or tea beverages. Non-enzymatic browning can produce brown, fluorescent, highly cross-linked pigments, such as melanoidin chromophores.
A possible mechanism for tea browning appears in the older literature [T. A. Geissman and D. H. G. Stout, Organic Chemistry of Secondary Plant Metabolism, Freeman, Cooper & Company, 1969, pg. 210-211]. A flavan-3,4 diol can participate in reversible, mild acid catalyzed reactions with catechins. Eventually, this reaction cascades to dimers that further condense to afford polymeric chromophores (browning pigments). The benzylic cation intermediates must be intercepted to prevent browning. Further, in some cases the pigments created have very high molecular weights, which can lead to the formation of floc within the beverages.
A common approach to inhibiting non-enzymatic browning in tea beverages is to include an antioxidant, generally ascorbic acid, in a beverage composition. However, if benzoic acid or salts thereof are also present in the beverage composition, ascorbic acid may promote decarboxylation of the benzoic acid to produce benzene. It would therefore be desirable to reduce or eliminate ascorbic acid from beverage compositions and employ an alternate edible acid to inhibit non-enzymatic browning in beverages, such as coumalic acid, while minimizing the formation of benzene.
It is an object of the invention to provide beverages and other beverage products having desirable appearance, taste and health properties. It is an object of at least certain embodiments of the invention to provide beverages and other beverage products having improved formulations. These and other objects, features and advantages of the invention or of certain embodiments of the invention will be apparent to those skilled in the art from the following disclosure and description of exemplary embodiments.